CHEN, X.-Y.; ZHANG, H.-C.; YANG, J.-Y. A new fossil species of Callipteris (Callipteridae) in the Early Permian from the Xishan Area in Beijing, North China. Phytotaxa, Auckland, New Zealand, v. 641, n. 4, p. 295–300, 2024. DOI: 10.11646/phytotaxa.641.4.6. Disponível em: https://phytotaxa.mapress.com/pt/article/view/phytotaxa.641.4.6. Acesso em: 5 dec. 2025.